Judging by the success of social games, I would say there is a "real-world" incentive to actually pay. Sure you don't have to, but then you might not be able to

Judging by the success of social games, I would say there is a "real-world" incentive to actually pay. Sure you don't have to, but then you might not be able to play FarmVille anymore! That's a real-world problem for a lot of people. It is true, however, that you'll never not be able to buy a house because of this though. Thank god for that.